Touching Lives - September 2004

Blindness in preterm babies -- new findings

The main characteristic of the disease is the growth of retinal blood vessels in the middle of the eye, and in severe cases retinal detachment can occur. The retina contains the light-detecting cells that enable us to see, and if it is affected in this way, blindness can result. In fact, in the UK alone, ROP is responsible for six per cent of childhood blindness.

Premature babies are often born with breathing difficulties. To help them they are resuscitated using oxygen and are often assisted by a ventilator. However, the very oxygen that helps these babies breathe can also cause ROP. The oxygen concentrations babies receive from their ventilators are variable (despite best efforts to control them), and research has shown that the more severe forms of retinopathy are related to varying levels of oxygen in the babies’ blood during the first two weeks of life.

£71,000 funding

With funding of £71,000 from Action Medical Research, researchers based at the Department of Child Life and Health in Edinburgh have been able to explore why high and fluctuating oxygen levels can have such devastating effects on normal eye development. The team found that both high and variable levels of oxygen reduce the amount of muscle and special supporting cells in the walls of retinal blood vessels in the eye.

The result is that the amount of blood vessels in the eye is increased, causing scarring on the retina, which may lead to impaired vision. Another exciting and unexpected result of this research has been the finding that astrocytes (special cells in the nervous system) may also be involved in the development of ROP. Further understanding of these processes may result in possible new treatments for ROP.

Professor Neil McIntosh, who headed the research, said, “The implication for this in our babies is clear. We need to manage them at slightly lower oxygen levels — which is easy to do. We also need to maintain their stability. This is more difficult, so is the area we will be concentrating our clinical research in the future”.